TRANSPORT UNIT WITH NEGATIVE PRESSURE DEVICE AND METHOD FOR TRANSPORTING TRAYS

Abstract

A transport unit that comprises a de-stacking device which is configured to drop trays from a stack of trays individually or in groups into a drop area, and a transport belt unit with a transport surface passing through the drop area for receiving and transporting away the dropped trays. The transport surface may comprise at least one opening. A negative pressure device may be provided to generate a suction force in the drop area through one or more of the openings of the transport surface, wherein the suction force sucks the dropped trays in the drop area in a direction towards the transport surface. This configuration reduces the rebound of the trays when they impact the transport surface as they are dropped. The invention also relates to a corresponding method for transporting trays.

Claims

1. A transport unit comprising: a de-stacking device configured to drop at least one tray from a stack of trays into a drop area; and a transport belt unit with a transport surface passing through said drop area for receiving and transporting away said at least one tray, wherein said transport surface comprises one or more openings; and a negative pressure device for generating a suction force in said drop area through one or more of said openings of said transport surface to apply said suction force to at least one tray in said drop area, said suction force applied in a direction towards said transport surface.

2. The transport unit according to claim 1, wherein the de-stacking device drops a group of trays onto said transport surface.

3. The transport unit according to claim 1, wherein said transport surface is at least in part formed by a link belt and a plurality of intermediate spaces between links of said link belt form said one or more openings of said transport surface.

4. The transport unit according to claim 1, wherein said transport surface is at least in part formed by two or more parallel transport belts, wherein each of at least one adjacent pair of said two or more parallel transport belts are separated by a gap, said gap having a width, said width being a distance in a direction perpendicular to a transport direction, and said gap separating each of said at least one adjacent pair of said two or more parallel transport belts comprising said one or more opening of said transport surface.

5. The transport unit according to claim 1, wherein said negative pressure device comprises a negative pressure generator and a suction attachment in fluid communication with said negative pressure generator, said suction attachment having a suction opening, wherein said suction attachment is disposed in said drop area on the side of said transport surface that is opposite to said at least one dropped trays.

6. The transport unit according to claim 5, wherein a cross-section of said suction opening covers at least a base surface of said at least one tray, wherein said base surface of said at least one tray engages said transport surface after said at least one tray is dropped.

7. The transport unit according to claim 1, wherein said trays are plastic trays, cardboard trays, aluminum trays, glass trays or trays of foamed material.

8. The transport unit according to claim 1, wherein said suction force applied by said negative pressure device is confined to said drop area.

9. A packaging system comprising a transport unit according to claim 1, wherein said trays are packages to be closed.

10. A packaging system according to claim 9, further comprising a tray sealer for closing said packages, wherein said transport belt unit is configured to transport said dropped packages to said tray sealer.

11. A method for transporting trays comprising: dropping one or more trays from a stack of trays into a drop area either individually or in groups, so that said trays are received by a transport surface of a transport belt unit passing through said drop area; generating a suction force using a negative pressure device; applying a suction force upon said one or more trays through one or more opening in said transport surface, said suction force applied in a direction towards said transport surface, said suction force applied at least concurrently with said dropping step; and transporting away said one or more trays with said transport belt unit after said dropping step.

12. The method according to claim 11, wherein said one or more opening in said transport surface is at least in part formed by a link belt and one or more intermediate spaces between two or more links of said link belt comprise said one or more opening of said transport surface.

13. The method of according to claim 11, wherein said one or more opening in said transport surface is at least in part formed by two or more parallel transport belts which are spaced apart from one another by a gap, and said gap comprising said one or more opening of said transport surface.

14. The method according to claim 11, wherein said trays are plastic trays, cardboard trays, aluminum trays, glass trays or trays of foamed material.

15. The method according to claim 11, wherein said suction force generated by said negative pressure device is confined to said drop area.

Description

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0027] In the following, an advantageous embodiment of the present invention will be explained in more detail making reference to the following drawings, in which the individual figures show:

[0028] FIG. 1 is a schematic top view of one embodiment of a packaging system with a transport unit according to the teachings of the present invention;

[0029] FIG. 2 is a schematic sectional view of the packaging system of FIG. 1 cut along the section line A-A;

[0030] FIG. 3 is a schematic partial view of a section through the packaging system of FIG. 1 cut along the section line B-B;

[0031] FIG. 4 is a schematic top view of one embodiment of the transport surface of a transport unit according to the teachings of the present invention; and

[0032] FIG. 5 is a schematic top view of another embodiment of the transport surface of a transport unit according to the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0033] The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

[0034] The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

[0035] FIG. 1 shows a schematic top view of a packaging system 1 with a transport unit 10 according to one embodiment. FIG. 2 shows packaging system 1 in a section along section line A-A from FIG. 1. Transport unit 10 of packaging system 1 comprises a de-stacking device 12 which is configured to drop trays 14 individually from a stack 16 into a drop area 18. It would also be possible to drop trays 14 in groups. In the embodiment shown, dropping a tray 14 is effected by releasing the lowermost tray 14 of stack 16. However, it would also be conceivable to provide a de-stacking device which actively drops trays 14. Transport unit 10 also comprises a transport belt unit 20 with a transport surface 22 passing through drop area 18. Dropped trays 14 are in the drop area 18 received by transport surface 22 and then transported away on transport surface 22 in a transport direction T. In the packaging system 1 of the embodiment shown, dropped trays 14 are first transported to a filling station 24 where they can be filled, for example, with foodstuffs. Trays 14 are then transported further to a tray sealer 26 which is configured to seal trays 14. Tray sealer 26 can be, for example, a sealing station for sealing plastic trays airtight with a film.

[0036] Transport surface 22 in the embodiment shown in FIG. 1 comprises a plurality of openings 28. Transport unit 10 comprises a negative pressure device 30 which is configured to generate a suction effect in drop area 18 through openings 28 of transport surface 22 which sucks dropped trays 14 in drop area 18 in the direction towards transport surface 22. For this purpose, negative pressure device 30 comprises a negative pressure generator 32, for example, a side channel blower and a suction attachment 34 connected thereto and defining a suction opening 36.

[0037] FIG. 3 shows a section of a sectional view through transport unit 10 in drop area 18 along section line B-B shown in FIG. 1. As can be seen there in detail, suction attachment 34 is arranged on the side of transport surface 22 that is opposite to that of dropped trays 14. The arrows in FIG. 3 represent the suction effect which negative pressure device 30 generates through openings 28 of transport surface 22. Dropped trays 14 in drop area 18 are sucked in the direction toward transport surface 22. Negative pressure device 30 sucks away an air cushion being present between tray 14 and transport surface 22 during the dropping of a tray 14. This configuration may result in preventing tray 14 from rebounding after impacting transport surface 22, thereby rendering its position or orientation on transport surface 22 being more predictable. In addition, the suction effect produces a pressure difference between an upper side of tray 14 and a base surface 38 facing transport surface 22. This pressure difference presses tray 14 onto transport surface 22. As a result, the friction of tray 14 on transport surface 22 is increased immediately after dropping, and tray 14 can be transported away more quickly and helping to ensure that transport surface 22 does not pass underneath tray 14 without taking tray 14 along.

[0038] The suction force generated by negative pressure device 30 may be confined to drop area 18 and may be concentrated there by suction attachment 34. It can thereby be ensured that the suction force does in fact act in drop area 18 to improves, reduce or prevent the rebound behavior of trays 14 impacting transport surface 22.

[0039] In the embodiment shown in FIGS. 1, 2 and 3, transport belt unit 20 comprises a transport belt 40 which forms transport surface 22. For driving and deflecting transport belt 40, transport belt unit 20 further comprises a plurality of drive or deflection rollers 42, a drive unit 43 and a frame structure for transport belt 40. Openings 28 in transport surface 22 are according to this embodiment realized by openings 28 distributed in transport belt 40 along its entire length. As shown in FIG. 1, these openings 28 can have a circular cross-section. However, other suitable cross-sections are also conceivable, such as, for example, a polygonal, an elliptical, a semicircular or an irregularly shaped cross-section. Slots are also conceivable, provided they permit the generation of the suction effect through transport surface 22. The distribution and size of openings 28 can be adapted to trays 14 being transported. Openings 28 can, for example, each have an opening area of less than 1 cm.sup.2, 2 cm.sup.2 or 5 cm.sup.2 or more than 1 cm.sup.2, 2 cm.sup.2 or 5 cm.sup.2.

[0040] However, it is also conceivable to form openings 28 in transport surface 22 in a different manner. For example, transport belt unit 20 could instead of transport belt 40 shown in FIGS. 1, 2 and 3, comprise a link belt 44 which forms transport surface 22 as shown schematically in FIG. 4. Link belt 44 comprises a plurality of links 46 which interact to form transport surface 22. Link belts 44 of various configurations are known and are particularly suitable for applications where the belt's flexibility or its characteristics when turning corners are important. As shown in FIG. 4, intermediate spaces between links 46 of link belt 44 form openings 28 of transport surface 22. Negative pressure device 30 can generate a suction effect upon dropped trays 14 through these intermediate spaces.

[0041] It is as a further alternative illustrated in FIG. 5, it is also conceivable that transport belt unit 20 may comprise a plurality of spaced transport belts 40 running in parallel and transversely relative to the transport direction T and forming transport surface 22. FIG. 5 shows a schematic top view onto such a transport surface 22. In this embodiment, it is not necessary to provide openings in transport belts 40 themselves. Openings 28 allowing the suction effect to be generated through transport surface 22 are already provided by the intermediate spaces between adjacent transport belts 40. The number of parallel transport belts 40 and the dimensions of the intermediate spaces between them can be adjusted depending on the application and the size of trays 14. It would of course also be conceivable to provide additional openings 28 in individual transport belts 40.

[0042] It would also be conceivable to alternatively provide the negative pressure device such that it generates a suction effect in the region of filling station 24 through one or more of the openings 28 of transport surface 22 which sucks trays 14 in the region of filling station 24 in the direction towards transport surface 22. Trays 14 would thereby have a better footing in the region of filling station 24, as a result of which slippage of trays 14 during the filling process can be prevented or reduced. In addition, the suction effect in the region of filling station 24 would have the effect that product portions which have undesirably ended up next to trays 14 on transport surface 22 during the filling process are sucked away through openings 28. The suction effect in the region of filling station 24 would therefore have a cleaning effect for transport surface 22 in addition to improving the footing of trays 14. This can be particularly advantageous when trays 14 are at filling station 24 filled with products comprising, for example, breading or powders. It is also conceivable that a suction effect is generated both in drop area 18 as well as in the region of filling station 24. This can be achieved by a common negative pressure device or by two separate negative pressure devices.

[0043] Instead of a sealing station, a lid closure station can also be provided for closing the trays, at which trays 14 are closed with a lid. This can be done manually or by machine. As an alternative or in addition to the above-described configurations of negative pressure device 30, the negative pressure device 30 can also be provided in the region of such a lid closure station so that the negative pressure device generates a suction force or suction effect through one or more openings 28 of transport surface 22 which in the region of the lid closure station sucks trays 14 in the direction towards transport surface 22. Trays 14 thereby experience improved footing which facilitates closure with a lid and prevents trays 14 from slipping when closed with a lid.

[0044] From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.

[0045] The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.